Vinylidene fluoride-based polymers are widely used as coating materials, lining materials or molding materials since they have excellent weather resistance, stain resistance, chemical resistance, anti-corrosion properties, and the like.
As is well known, however, vinylidene fluoride-based polymers are chemically inert. Thus, when used as coating materials, they adhere to substrates poorly. In order to improve the poor substrate adhesion properties, it has been proposed to compound an acrylic resin to vinylidene fluoride-based polymers. See, for example, U.S. Pat. Nos. 3,324,069 and 4,642,249, and Japanese Laid-Open Pat. Application No. 174247/1977. The adhesive properties of these acrylic resin-compounded vinylidene fluoride-based resin compositions are unsatisfactory. It is necessary to utilize a primer, such as a primer comprising an epoxy resin and urethane resin, in conjunction with these compositions. Alternatively, it is necessary to compound a large amount of acrylic resin to the vinylidene fluoride-based polymer. Compounding large amounts of acrylic resin, however, reduces the inherent properties of the vinylidene fluoride-based polymer. As a result, the aforementioned excellent properties of the vinylidene fluoride-based polymer are not sufficiently exhibited.
The present invention is intended to overcome the above problems. An object the invention is to provide a vinylidene-fluoride based polymer-containing coating composition capable of forming a coating having excellent weather resistance, stain resistance, chemical stability, surface lubricity, and the like, and excellent adhesion to substrates.